Bandages and wound dressings are simple, familiar devices. In an effort to hasten the wound healing process or reduce the risk of infection, there have been many recent efforts to redesign, or sometimes redefine, a bandage. Few people have enjoyed the benefits of some new bandages, because they are either too complex or too expensive.
The major advances in the art of wound healing are usually either improved methods for reducing infection or stimulating cell repair. It is now known that a moist wound heals faster and is less likely to scar than a dry wound, so the use of traditional bandages to keep a wound moist and protected is correct. It is also known that silver is an anti-microbial agent, so there are numerous products that deliver silver to a wound, such as Smith & NephewSM ACTICOAT 7™, Johnson & Johnson® ACTISORB™, and Bristol-Meyers SquibbSM HYDROFIBER®.
Covering a wound is easy, and there are numerous products that fill that need. Delivering silver to a wound, however, has posed many difficulties because silver is a metal. Some methods resort to using silver crystals, which have a large relative surface area. Colloidal silver, silver salts (e.g. silver nitrate) and silver compounds (e.g. silver sulfadiazine) have been used to make creams and ointments. Creams and ointments are popular in the field of medicine because they are easy to use and familiar.
There are devices that rely on either an external electrical power source or a direct reaction between silver and another metal to generate the production of silver ions. One technology, described in U.S. Pat. Nos. 4,657,808 and 4,529,623 to Frederick Maggs consists of activated carbon with silver dispersed within it. Other technologies, described in U.S. Pat. Nos. 5,681,575, 5,753,251, 5,770,255, and 5,837,275 to Dr. Robert Burrell, et al., use vapor deposition techniques to apply a coating of silver onto a medical device. Yet another technology, described in U.S. Pat. No. 5,814,094 to Dr. Robert O. Becker, uses electricity (often from a coin battery) to produce free silver ions that may penetrate into the wound tissue. And yet another technology, described in U.S. Pat. No. 6,522,918 to Dr. William E. Crisp, et al., combines silver and another metal-bearing material within a thickness of material, such as a sponge. Unfortunately, these devices may require expensive manufacturing processes, and the devices themselves can be complex and cumbersome.